Multiple switch



Jam 25 1927' G. w. GRISDALE MULTIPLE SWITCH Filed OG.. 3l, 1923 2 Sheets-Sheet l S .nu

NVENTR George I4( @fzlsaa/e,

m o s o a o l n g o o.. o n n u o u n c g o n o o l 0 o o u \o s o 0 o o o o n n 1,615,450 Jan- 25 1927' G. w. GRISDALE MULTIPLE SWITCH Filed Oct 31 1923 2 Sheets-Sheet 2 mvENToR @gorge I4( @risd/e TTORNEY Patented Jan. 25, 1927.

UNITED STATES `1,615,450 PATENT OFFICE.N

GEORGE W. GRISDALE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE BROWN INSTRUMENT COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A COR- PORATION OF PENNSYLVANIA.

MULTIPLE SWITCHl Application led October 31, 1923.

` The present invention relates to electric switches, and more particularly to an automatic switch for connecting a plurality ofwhich the danger of short circuits and loose connections is reduced to a minimum; to provide a switch arranged to successively connect a plurality of separate circuits to a common circuit; and to provide other improvements as will hereinafter appear.

In the accompanying drawings, Fig. 1 represents diagrammatically an electrical system including a selecting switch embodying one form oi the present invention; Fig. 2 represents an elevation of the inner face of one of the side plates of the switch; Fig. 3 represents an elevation of the outer face of the same plate; Fig. 4 represents an elevation of the inner face of the other side plate of the switch; Fig. 5 represents an elevation of the outer face of the plate of Fig. 4; Fig. 6 represents a side elevation of the contactor member of theswitch; Fig. 7 represents a front elevation of the contacter member; and Fig. 8 is a section through the switch on a plane passing through the axis of the latter.

Referring to the drawings, one form of the present invention comprises a switch 10, which in Fig. 1 is included in an electrical system comprising a plurality of thermocouples 11 to 16 inclusive, which are respectively connected by pairs of conductors, as will be presently explained, to one side of the switch` while the opposite side of the switch isconnected by conductors 17 and 18 to a measuring instrument 19, which may be either of the indicating or recording type.

The function of the switch 10 is to auto- Serial No. 671,961.

corded by that instrument in any well known manner. It will be understood that the system shown in Fig. 1 is only by way of example, and the vswitch may be used for the successive connection of any other series of electrical circuits, and its use is not limited to a combination including thermo-couples, and the present illustration is only by way of example.

In the preferred form of the invention, the switch 10 comprises a casing 2O in the form of an annular ring and two closure plates 21 and 22 respectively seating 'in and fitting snugly into the opposite ends of the casing 20. The closure plate 21 in this instance is arranged to be connected to the multiple circuits including the thermo-couples, and to that end consists of an inner circular ring of segments 23 and an outer concentric ring of segments 24:, the two segmental rings being formed of conducting material and molded into bakelite or other material forming the plate 21. Concentrically arranged with respect tothese ring segments and axially of the plate 2l is an opening 25, suitably bushed to form a bearing for a rotatable spindle 26:

'For the purpose of electrically connecting each of the segments of the two rings into the respective circuits, the respective segments 23 are provided with terminal posts 27, and the segments 24 are similarly respectively provided witn terminal posts 28, the two sets of posts passing through the plate 21 and projecting exterior thereof for purposes of connection with the circuit wires of the respective circuits to be controlled by the Switch. In this instance, since there are six circuits to be separately controlled, there are six segments in each of the ring contactfelements and therefore twelve terminal posts projecting exterior of the plate 21, and these posts are preferably arranged in pairs diametrically opposite and spaced at 60 degree intervals. For convenience of illustration, the segments 23 are separately identified by reference letters A, B, C, D, E and F and the segments 24 by reference letters G, H, I, J, K and L, and therefore the terminal posts are identified by reference characters 27 A to 27 F inclusive and28 G to 28 L inclusive. Thus, the thermo-couple 11 has one conductor 30 connected to -terminal post 28 G, and the other conductor 31 connected to terminal post 27 D; the thermocouple 12 has one conductor 32 connected to terminal post 28 H, and the other conductor connected to terminal post 27 E; the thermo-couple 13 has one conductor 34 connected to terminal post 28 I, and the other conductor 35 connected'to terminal post 27 F; the thermo-couple 14 has one conductor 36 connected to terminal post 28 J, and the other conductor 37 connected to terminal post 27 A; the thermo-couple 15 has one conductor 37 connected to terminal post 28 K, and the other conductor 38 connected to terminal post 27 B; the thermo-couple 16 has one conductor 39 connected to terminal post 28 L, and the other conductor 40 connected to terminal post 27 C.

For the purpose ot connecting the switch 10 to the electrical instrument 19, the plate 22 is provided with two concentric continuous rings 41 and 42 ot conducting material, which are arranged concentric with respect to each other and also with respect to an axial opening 43, which is bushed to receive the opposite end of the spindle 26. These contact rings 41 and 42 are molded in the bakelite or other insulating material forming the plate 22, and the ring 41 has an integral terminal post 44 projecting to the outside ot' the plate 22, and the ring 42 has a similar terminal post 45 also projecting to the outside ot' the plate 22. These posts 44 and 45 are respectively connected to conductors 17 and 18 which t'orm extensions of the operating circuit ot the instrument 19.

F or the purpose of successively connecting the terminals ot the respective controlling circuits and the circuit of the instrument 19, includingr the conductors 17 and-18, a rotatable contactor 46 is provided, the body portion 47 of which is formed of bakelite or other suitable insulating material made fast to the spindle 26 and carrying upon its periphery two contactor elements 48 and 49, cach ot' which is pivoted intermediate its length to the body 47, as shown at 50 and 51. The contactor 48 is provided with two oppositely disposed laterally projecting fingers 52 and 53. carrying respectively platinum contactor pieces 54 and 55, which are arranged to ride respectively upon a segmental platinum contact track 56 upon the ring segment 23 and upon a platinum contact track 57 on the ring 41. A coil spring 58 normally acts upon the contactor 48 to hold the contactors 54 and 55 pressed normally7 toward the axis of rotation or toward the spindle 26. The contactor member 49 is likewise formedwith two oppositely disposed projecting fingers 59 and 60, carrying contactor platinum pieces 61 and 62, which are arranged to ride respectively upon the segmental platinum contact track 63 upon the segments 24 and upon a continuous contact track 64 upon the ring 42, being held inengagement therewith by a coil spring 65 located between the contactor 49 and the switch body 47. In this connection, it will be noted that the contactor 48 is radially disposed the same distance from the spindle 26 as is the ring of segments 23 and the continuous ring 41, and the contactor 49 is similarly located the same radial distance from the spindle 26 as the ring segments 24 and ring 42.

The thickness of the body 47 ot the switch 46 is such that in assembled condition of the parts it lits snugly between the two opposed sets of fixed contacts, while the spring pressed contact pieces project at the sides to seat upon the respective contact tracks and are firmly pressed thereagainst by the respective springs 58 and 65.

The spindle 26 may be rotated by any well known step by step movement, and the arrangement in the present instance is such that it will have a periodic movement imparted to it which turns the contactor pieces 54 and 55 and 59 and 60 through a 60 degree are at each partial rotation of the spindle 26. It will further be understood that the casing 2O of the switch, together with the end plates 21 and 22, are stationary and remain fixed, while the contactor member 46 receives only the periodic rotary movement.

Thus, in assembled condition of the switch, and assuming itto be connected in a system such as shown in Fig. 1, but one thermocouple will be connected to the instrument 19 at a time, the particular one being determined by the position of the switch contactor pieces 54 and 59 with respect to the segments 23 and 24. For example, it thermocouple 11 is connected to the instrument 19, the circuit from such thermo-couple will be by the conductor 30 to terminal post 28 G, segment 24 G, track 63, contact piece 59, contactor element 49, contactor piece 62, track 64, ring 42, terminal post 45, conductor 18, instrument 19, conductor 17, terminal post 44, ring 41, track 57, contactor piece 55,

contactor element 48, contactor piece 54,l `track 56, segment 23 D, post 27 D, conductor 31 to the other binding post of the thermocouple 11. As long as this circuit is closed by the switch remaining in this set position, the temperature measured by the thermocouple 11 will be indicated or recorded upon the instrument 19. At the end ot the predetermined period the rotatable switch member 46 will be shifted through the predetermined arc necessary to bring the contact pieces 54 and 59 into engagement with the next pair of contacts 24 L and 23 C, and thus connect the thermo-couple 12 to the instrument. In this way the successive circuits are connected one at a time to the instrument 19, and the readings observed or recorded.

From the foregoing, it will be apparent that a complete rotary circuit selecting u switch has been provided, wherein the fixed `a unitary compact structure contact making elements are rigidi molded into the parts supportingl them and thereby the use of screws, rivets, or other separable fastening means is eliminated, and produces Lparticularly adapted for the purpose intende Furthermore, the periodically rotatable contacter comprises few parts, and these are arranged to give positive and effective current conveying means from one set of contacts to the other `and the elimination of loose connections or short circuits between any of the moving or fixed parts.

Although but one form is shown in which this invention may be embodied, it is to be understood that the invention is not limitedto any specific constructiom'but might bel applied in various forms without departing from the spirit 'of the invention or the scope of the appended claims. v

Having thus described my invention, -I claim: J

1. A multi le switch comprising a casing, a rotating eement within said casing, a contact member secured toy said casing and comprising a cylindrical portion within said casing and coaxial with said element, a series of contacts secured to said casing and comprising portions spaced about the axis of rotation of said element and forming sections of a cylinder coaxial therewitli'and in end to end relation with the cylindrical portiii of said contact member, and a second contact member carried by said rotatable element and engaging a cylindrical surface of the first mentioned contact member and a c lindric'al surface of one or another of saidy'contacts depending on the angular position of said element.

2. A multiple switclircomprising a casing having end walls of insulating material, a rotating element within said casing. a contact member secured to one of said end walls within said casing.

and comprisin a cylindrical portion within said casing an coaxial with said element, a

series ofcontacts secured to the other end wall and comprising portions Within said casing spaced about the axis of said element and forming sections of a cylinder coaxial v therewith and in end to end relation with the cylindrical ortion of sai-d contact member. and a secon contact membei` carried by said rotatable element and engaging a cylindrical s urface of the first mentioned contact membery and a cylindrical surface ot one or an-e vals l.about a circle coaxial with said rotatf able element and corresponding in diameter to the smaller of said ring contact members and lin end/to end relation with the latter,

and the contacts of the other set being located at intervals about a circle coaxial `with said rotatable element and corresponding in diameter to the vlarger of said ring contact members and in end to end relation with'cthe latter, and two contactors mounted on vsaid rotatable element and angularly displaced from one another with respect to tlie axis of said element, one of said contactors connecting the larger of said ring contacts successively to the different contacts of said one set as the element is rotated, while the other contact member similarly connects` the smaller of the ring -contact members of the contacts of said second set.

Signed at Philadelphia, in the county of Philadelphia, State .of Pennsylvania, this 28 day of September 1928.

GEoRE w. GRISDALE. 

